Union J star JJ Hamblett became a father on Thursday morning (28.11.13).
The 25-year-old star was delighted that girlfriend Caterina Lopez safely delivered a baby boy who weighed in at 6lbs.
He tweeted: ''Its official at 9 30am today I became a Daddy The healthy little boy has arrived at a weight of 6lb!!!!! soooo happy right now :)))) xx (sic)''
An hour later he announced the name of the little one, writing: ''PRINCETON J. ALEXANDER (sic)'', and attached an image showing the soles of the tiny tot's feet.
Caterina went into labour on Wednesday (27.11.13) and JJ had been anticipating the arrival of the little one since then, sharing the exciting moments with his fans.
He wrote: ''AND NOW WE WAIT!!! :-))))))) x ... NOT LONG NOW!!!!!! Sooooooo excited :))))) xxx (sic)''
Both fans and other stars were quick to send their love and congratulations to the couple.
JJ's bandmate George Shelley wrote: ''Congratulations JJ and Cat! New little one in the family now so proud of you both! I'm not the youngest member anymore!! Haha Love You!''
Josh Cuthbert added: ''SOOO HAPPY for JJ and Cat!! Its an amazing day and couldnt happen to 2 more amazing people. Chuffed to bits. The baby is gonna be beautiful (sic)''